MULTIMODAL EQUILIBRIUM MODELS
FOR PREDICTING INTERCITY FREIGHT FLOWS
 

J. Enrique Fernández L., Joaquín de Cea Ch. and Alexandra Soto O.
Transport Engineering Department
Universidad Católica de Chile
Casilla 306, FAX: (56-2) 686 4270 Santiago, CHILE.
   
  ABSTRACT
 


In this paper new approaches to the intercity freight transportation system modeling are developed and analyzed. We take an equilibrium supply-demand approach, where the demand side represents the behavior of shippers (cargo owners) and the supply side represents the behavior of carriers (transportation operators). Shippers decisions considered include choice of destination, mode, carrier for pure modes and transfer point for combined modes. Carriers take routing decisions over a multimodal, multiproduct and multioperator network. We develop several simultaneous mathematical formulations to find consistent solutions for flows and level of services, each of them based on particular assumptions on the costs perceptions taken into account by shippers and carriers. Special rationality conditions are shown to be required with respect to fares charged and network routing decisions, in order to be able to obtain consistent system equilibrium solutions. The properties of solutions to the models formulated are derived and analyzed. Finally a solution approach is proposed.

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